Description:
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I am submitting what in my view is uncorrect behaviour of the [] operator for arrays. It is a special case when the last element of the array is removed with unset() and then a new element is added using the arrname[] = xxxx syntax.

Reproduce code:
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$teststring = "let's test this";
$testarr = explode(' ', $teststring);
print_r($testarr);echo "<br />";
unset($testarr[2]);
print_r($testarr);echo "<br />";
$testarr[] = 'new';
print_r($testarr);

Expected result:
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Array ( [0] => let's [1] => test [2] => this )
Array ( [0] => let's [1] => test )
Array ( [0] => let's [1] => test [2] => new )

Actual result:
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Array ( [0] => let's [1] => test [2] => this )
Array ( [0] => let's [1] => test )
Array ( [0] => let's [1] => test [3] => new )